Key takeaways
- These medicines work alongside diet and activity, not instead of them.
- Weight tends to return after stopping unless habits and a maintenance plan are in place.
- Some of the weight lost is muscle, which protein and strength training help protect.
- A small group of people should not take them, including those with certain thyroid cancers in the family or past pancreatitis.
- Buying them without a doctor's assessment is unsafe and, in India, they are prescription-only.
Do these medicines replace diet and effort?
Half the people I meet think these medicines are magic. The other half think they are dangerous. Neither group is entirely right, and neither is entirely wrong. Let me go through the ten myths I hear most.
Myth 1: "Weight loss medicine is a shortcut for people who will not diet."
Obesity is a long-term medical condition influenced by genes, hormones, sleep, stress and environment, not only willpower. The NHS describes GLP-1 and GIP medicines as treatments that reduce appetite and help you feel fuller for longer, prescribed alongside diet and lifestyle advice. You still need to eat fewer calories and be physically active while taking them.
So the medicine changes how hard the work feels. It does not remove the work.
Myth 2: "Everyone loses the same amount."
In the STEP 1 trial, adults on weekly semaglutide lost an average of 14.9% of their body weight over 68 weeks, compared with 2.4% on placebo. But averages hide a wide range: some people lose much more and some much less. Your dose, side effects, sleep, activity, other medicines and biology all play a part.
Myth 3: "All the weight you lose is fat."
Not quite. Whenever weight falls quickly, by any method, some of the loss is muscle. Studies of GLP-1 medicines have measured varying amounts of lean mass loss. Endocrinology guidance advises around 1.2 to 1.5 g of protein per kg a day and regular resistance training to protect muscle, and notes that protein alone may not be enough without strength work. See muscle loss on weight loss injections.
Are these medicines safe?
Myth 4: "These medicines cause thyroid cancer."
The honest answer is more nuanced. Semaglutide caused thyroid tumours in rats, and MedlinePlus states it is not known whether it does so in humans. Because of this, people with a personal or family history of medullary thyroid cancer, or of MEN 2 syndrome, should not take it. Ordinary hypothyroidism is a different condition and does not by itself rule out treatment. Read thyroid and weight myths.
Myth 5: "Anyone who wants to lose weight can take them."
No. Eligibility depends on your BMI, waist, health conditions and history. Reasons a doctor may advise against them include past pancreatitis, certain thyroid cancers, pregnancy or plans to conceive soon, breastfeeding, some stomach problems and a history of eating disorders. See who should not take weight loss injections and who is eligible for medical weight loss in India.
Myth 6: "The side effects are dangerous for most people."
Most side effects are digestive: nausea, vomiting, diarrhoea, constipation and tiredness, often worst while the dose is being increased. The NHS also lists hair loss among common side effects, and it advises avoiding alcohol because it can worsen nausea. Serious problems such as pancreatitis, severe allergic reactions and sudden vision loss are rare but need urgent care.
| Symptom | What to do |
|---|---|
| Mild nausea, early fullness | Smaller meals, eat slowly, avoid oily food; tell your doctor at review |
| Constipation | Fluids, fibre, movement; ask about a gentle laxative |
| Repeated vomiting or unable to keep fluids down | Contact your doctor the same day |
| Severe stomach pain spreading to the back | Seek urgent care (possible pancreatitis) |
| Pain under the right ribs after meals, yellow eyes | See a doctor promptly (possible gallbladder problem) |
| Sudden change in vision | Seek urgent care |
For practical tips, see managing nausea on weight loss injections.
What about doses and stopping?
Myth 7: "A higher dose means faster, better results."
Doses are increased step by step over weeks to months, mainly so your stomach can adjust. Rushing the dose increases nausea, vomiting and dehydration. The US FDA has reported hospitalisations linked to dosing errors with unapproved products, including people taking doses beyond approved labelling. See, what happens is, the right dose is the lowest one that works for you, with side effects you can live with. The dose is the skill, and it is a doctor's decision.
Myth 8: "Once I lose the weight, I can stop and it will stay off."
This is the myth that causes the most disappointment. Follow-up of trial participants who stopped semaglutide found that much of the lost weight returned within about a year when nothing replaced the medicine. The NHS says people stopping these medicines should be offered support to stay at a healthy weight.
That is very important to understand: the plan for stopping should exist before you start. Read how to come off weight loss medicine without regaining the weight.
Who can get them, and where?
Myth 9: "They are only for diabetics."
Semaglutide was first used for type 2 diabetes, but the Indian government has stated in Parliament that the Central Drugs Standard Control Organisation (CDSCO) has approved orlistat, semaglutide and tirzepatide for weight management, to be sold on a doctor's prescription and used under medical supervision.
Myth 10: "It is fine to buy them online or from a gym."
It is not. Your gym trainer may know squats; he does not know your pancreas. Regulators abroad have found counterfeit products containing the wrong ingredient, the wrong amount or none at all. Injectable pens also need proper refrigeration, which is hard to guarantee when they are shipped across India in summer. A doctor-led programme, online or in person, should include an assessment, blood tests, a signed prescription and follow-up. Read is online doctor-led weight loss safe in India.
How I approach this at Dr Tvacha
I took GLP-1 treatment myself before offering it. I do not like injections, so I understand the hesitation many people feel. In the Endgame Weight Programme, every plan starts with a Rs 499 eligibility video consult. I explain the options and you decide; if medicine is not suitable, I say so. When it is, the plan rests on the Triad of dose, protein and strength training, with a written taper and maintenance plan from month one. Details are on the weight loss page.
Frequently asked questions
Do I have to take weight loss medicine for life?
Not necessarily, but stopping without a plan often leads to weight regain. Some people taper down slowly under supervision, some continue on a lower maintenance dose, and some stop once strong habits are in place. Which route suits you depends on your health, your weight history and how your body responds. Discuss the exit plan before you start.
Are weight loss injections painful?
Most people find the injection quick and tolerable. I say this as someone who dislikes injections: the pen uses a very fine needle, similar to an insulin needle, injected under the skin of the abdomen, thigh or upper arm. Sensation varies between people, and the clinic should show you how to inject properly. Mild redness or itching at the site can occur.
Will I lose muscle on GLP-1 medicine?
Some muscle loss is likely during any significant weight loss. You can reduce it by eating enough protein, around 1.2 to 1.5 g per kg a day as guided by your doctor, and doing resistance training two to three times a week. Losing weight at a steady pace rather than as fast as possible also helps protect muscle.
Is it safe to take weight loss medicine if I have thyroid problems?
A treated, stable underactive thyroid does not usually rule out these medicines. However, a personal or family history of medullary thyroid cancer or MEN 2 syndrome is a reason not to take them, because of findings in animal studies. Tell your doctor about any thyroid surgery, nodules or thyroid cancer in your family before starting.
Can I drink alcohol on weight loss medicine?
The NHS advises avoiding alcohol on semaglutide because it can make nausea and vomiting worse. Alcohol also adds calories, increases dehydration and is a major cause of pancreatitis, a rare side effect of these medicines. If you choose to drink at a wedding or event, keep it light and talk to your doctor first.
Written by
Dr Amit KarkhanisAesthetic Physician · MBBS, Dip. Dermatology (UK) · Reg. No. 2001/02/1124Founder of Dr Tvacha, practising in Thane since 2005. Leads the weight loss and hair programmes.
Sources
- Obesity treatment (NHS)
- Semaglutide (NHS medicines)
- Semaglutide injection (MedlinePlus, US National Library of Medicine)
- FDA's concerns with unapproved GLP-1 drugs used for weight loss (US FDA)
- CDSCO has approved 3 drugs for weight management, government tells Rajya Sabha (ETV Bharat)
- Considerations for patients on obesity medication (American Association of Clinical Endocrinology)
This article is for general education and does not replace a consultation. Medicines and treatments are prescribed only after a doctor's assessment. Last reviewed 25 October 2026.